Not so much direct competition as slight genre & event film fatigue. Even if Star Wars, JL & Avengers are all 10/10 films with zero overlap in box office run it's difficult to get as excited about all 3 individually as I would if they weren't all coming out in the same year. My excitement for Amazing Spider-man for eg was minimal this year as I could only think Avengers & TDKR 1st. Spidey came & went, was fine & if it had been coming out another year I would have been anticipating it daily 2 years out.

You still saw Spider-Man though, right? People bring up genre fatigue every year. It's really not a factor, if a movie looks good people will see it. And how amped up people are beforehand compared to other movies that aren't directly competing doesn't really matter, tickets cost the same whether they were purchased by someone who followed the entire production, someone who thought the trailer looked neat, or someone who was just bored and picked a movie. I spent the same amount of money on tickets for The Dark Knight Rises, The Avengers, Amazing Spider-Man, Brave, and whatever else I saw.